Superfluid Helium – Zero Viscocity

Science is often surprising. Basic stuff runs on fairly simple “rules”, but the simple rules don’t cover everything – so when you see stuff that doesn’t abide by the simple rules, you can’t just ignore or dismiss what you see. To me, this is awesome rather than scary. It makes science extra cool.

We generally regard substances as having three possible states: solid, liquid, gas. It’s a simple rule of thumb (rather than a rule) and works well for our everyday environment. At room temperature, many things are always solid to us, and many things are always gas. In the video below, helium shows us some extra quirks when it is made particularly cold.

So how about those simple rules or “rules of thumb”. Well, they are a simplified version of the full picture – and thus cover many cases, but not all. Newtonian physics work really well for the world around us, but not when looking at really big stuff (we need general and special relativity for that) or really small stuff (quantum physics).

In Australia, we are taught “look right” first when crossing the road. In The Netherlands, where I was born, I was taught “look left” first. This is pretty clear for an example: in the Netherlands cars drive on the right hand side of the road, while in Australia they drive on the left. But we don’t learn “look towards the side where the cars normally come from” as that’s way longer, and actually problematic: if you don’t remember, and there are no cars immediately visible, does that mean there can’t just be a car about to race around the corner towards you?
Of course, the full rule is (for Australia): “look right, left, right” and that actually covers various eventualities.
Nevertheless, I was once at a training course in London (UK) and had to save fellow students from Brazil from oncoming traffic several times (by giving them a shove backwards as they started to cross), as they were not used to cars coming from the right. Blind habits can be dangerous…..

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